Storm brews over the use of HDR Photography

HDR Photography or ‘High Dynamic Range’ is a photographic and imaging technique which causes some controversy, especially amongst ‘purists’.

Here are four variants of a storm scene this weekend over Inverness, all produced using HDR Photography techniques:

Four, differently processed, HDR Photographs

Some purists think HDR as a photographic technique is ‘cheating’ or too unrealistic looking – sometimes it can be! The second pair of images above, in particular, are unrealistic – deliberately so. However, they went down a storm on Facebook!

I make no bones about it – I like HDR Photography – in this article, I’ll explain why.

What is HDR?

The technique of HDR Photography involves taking so-called ‘bracketed’ images, which simply means a series of images taken, or the same subject, at different exposure levels. The images are then combined, or ‘blended’ using software to create a composite image.

Here are the unprocessed bracketed images that were combined to create the above HDR series of images.

Why would you do this? Simply because the camera, clever though it is, cannot record the range of contrast (light levels) that the naked eye can cope with. As a result, the camera isn’t able to properly capture an image that has a high dynamic range i.e. a lot of contrast, i.e. areas of high contrasting light and dark areas. What does this mean? it means that the image will either be exposed correctly for the dark/shaded areas, with the sky ‘blown out’ (over exposed), just a mass of white with no detail); or it will be exposed correctly for the light areas i.e. the sky, in which case everything else will be too dark, possibly just a black silhouette.

For scenes with a medium level of contrast, the scene can be ‘recovered’ in editing (post-processing) by reducing the brightness of the highlights and/or increasing the shadows. This won’t work for areas that are totally white or black, as no detail has been captured i.e. no shades.

Here’s the third of the above images processed as best I can without HDR blending:

Can’t I Use Filters Instead?

One way to try to overcome this is to use a filter. A polarising filter can help a little, reducing some of the brightness in things like reflections. The main type of filter that can help is a graduated neutral density filter. This is a filter that has contrasting areas of light and dark areas, which can be used to balance out a scene, as far as what the camera sees. This type of filter only tends to work for landscape photography when the sky is bright and the horizon is relatively flat, so the sky can effectively be darkened by the filter. This allows you to expose more to capture the detail in the shadows.

Filters do have their place. It is good to experiment with both these methods.

However, where the areas of light and shade are not uniformly in one-half of the image and the other e.g. where there is a horizon between a bright sky and a darker land/sea, then the filter cannot fully compensate. I’ll write another blog post about using filters.

Reasons for Using HDR

Using the blending approach, the HDR software can compensate appropriately across the whole image, rather like your eye does. This can produce a natural looking image.

The HDR software also often allows you to exaggerate its effect and indeed apply many different effects, to differing degrees. This can result in a very unrealistic image, often cartoon looking. Here’s a deliberate example:

House of Horrors – plenty of HDR used here, for effect

This was made black and white for added effect!

There are many different software options available to HDR process your bracketed images. I sometimes use the HDR option in Lightroom, however, it doesn’t give much control, so I prefer to use Photomatrix Pro, which is available as a Lightroom software plugin.